Coral Reefs are often thought to be rocks, stones or plants on the sea bed; however Coral is actually composed of the limestone skeletons of a tiny spineless animal called Coral Polyp,When a coral dies, it leaves its skeleton of limestone behind Young corals attach themselves to the old skeleton and the cycle starts all over again. Coral reefs are usually found in shallow tropical waters located near the equator, shallow water is ideal for corals to survive as they need the sunlight.